Originally Posted by Nate

Hey,

I will go out on a limb here, and take a guess that there is a protein coating on the top of your water. Usually in smaller tanks, that do not have an overflow you end up with a coating on the top of your water that looks like oil. Take a look, I would be willing to bet money that that was at least part of the problem.

What happens is the protein prevents any oxygen exchange. That is more than likely why the bubbler is helping. I would think that it would be a worthwhile investment to buy a skimmer (if you dont have one) and a surface skimmer (the make them for aquaclear, fluval and ehiems). What this will do is get the protein back into the water, where you can get it out through skimming or h2o changes. The other option is to use your gravel vac in reverse and surface skim the protein off.

Of course if this is not the problem, sorry for blabbing...but good luck anyways.

NAte